I have read the thread about the problems associated with long focal length focusing and using an RC at 1600mm I am sadly falling foul of the issues. My focus with the auto routines is always a fairly consistent amount away from good focus. I was thinking that in order to focus in Ha for example I have an offset - Is there a way to add an offset with the luminance filter that is actually focusing?
If this is doable, I could run the focus routine and add a +30 or so offset that I have found it always needs as a tweak to really nail that focus. Interestingly I have always found the focus to be out in the same direction, so this would definitely cure the problem.